1. Field of the Invention
The present invention relates to radio frequency identification (RFID) systems, and more particularly, to a vehicle windshield containing an embedded RFID transponder permitting vehicle-related data to be readily stored, remotely accessed, and updated.
2. Description of Related Art
Every one of the millions of motor vehicles operating in this country and abroad has associated vehicle-related data that must be made readily accessible to the operator and others. For example, certain state and local governments require certain kinds of vehicle-related data to be displayed on the exterior of the vehicle, such as current vehicle registration, safety inspection, valid handicap status certification, and emission control certification. Law enforcement personnel may additionally require other kinds of vehicle-related data to be maintained within the vehicle, such as proof of ownership and insurance coverage. The vehicle owner/operator and/or other private entities may additionally require still other kinds of vehicle-related data in the course of ordinary use of the vehicle, such as for parking access validation, monitoring and revenue collection. Separate tracking and storage systems exist for each of these different types of vehicle-related data.
The most common form of vehicle-data storage device is a sticker containing alphanumeric data. Vehicle stickers may be imprinted with colorful indicia and/or data, and can be affixed to the exterior of a vehicle in a highly visible manner. Moreover, vehicle stickers cannot be easily removed from a vehicle, making them inherently theft-resistant. A significant drawback with vehicle stickers is that their information capacity is rather limited and cannot be easily updated. As a result, vehicle operators must periodically replace or cover over expired stickers with new stickers. The difficulty of removing expired stickers is also a disadvantage, as many vehicle owners consider the proliferation of vehicle stickers to be an eyesore that mars the beauty and value of their vehicle.
Another common form of vehicle-data storage device is a card encoded with data, such as human-readable data (i.e., alphanumeric characters) or machine-readable data (i.e. optical indicia, such as bar code symbols, or magnetically recorded data). An advantage of an encoded card is that it generally has a much greater data capacity than that of a sticker. Nevertheless, the card is not affixed to the vehicle exterior and must therefore be kept either within the vehicle or on the vehicle operator's person, thereby increasing the risk that the card will be lost or stolen. Another drawback with an encoded card is that it is usually not visible from the exterior of the vehicle to the same degree as a sticker.
In the automatic data identification industry, the use of RFID transponders (also known as RFID tags) has grown in prominence as a way to obtain data regarding an object onto which an RFID transponder is affixed. An RFID transponder generally includes a semiconductor memory in which information may be stored. An RFID interrogator containing a transmitter-receiver unit is used to query an RFID transponder that may be at a distance from the interrogator and moving at highway speeds. The RFID transponder detects the interrogating signal and transmits a response signal containing encoded data back to the interrogator. Such RFID transponders may have a memory capacity of several kilobytes or more, which is substantially greater than the maximum amount of data that may be contained in a bar code symbol or other types of human-readable indicia. Further, the RFID transponder memory may be re-written with new or additional data, which would not be possible with a printed bar code symbol. RFID transponders may also be readable at a distance without requiring a direct line-of-sight view by the interrogator, unlike bar code symbols or other types of human-readable indicia that must be within a direct line-of-sight and which may be rendered entirely unreadable if obscured or damaged.
While RFID transponders are increasingly used with vehicles, such as for vehicle toll collection, RFID transponders have not been uniformly accepted as a vehicle-related data storage device. One reason for this lack of commercial acceptance stems from the size of the RFID transponder package, which has been driven in part by the size requirements of the antenna. The RFID transponders cannot be obscured by metallic objects that would impede RF communication with the RFID transponders. While the RFID transponders can be provided in a package that may be mounted inside or outside of the vehicle, such packages are susceptible to theft, weathering and damage, and do not convey visual information to the same degree as a vehicle sticker. Another drawback with RFID transponders is that automobile manufacturers are including conductive layers within vehicle windshields, which hinders the ability to communicate with an RFID transponder disposed within the vehicle. A final drawback of RFID systems is the lack of standardization between data formats necessary to permit different types of vehicle-related data to be stored in a single device. An industry group referred to as the Dedicated Short-Range Communication (DSRC) has formed a sub-committee to develop a uniform standard for vehicle RFID systems, but to date no such uniform standard has been adopted.
Accordingly, it would be desirable to provide an unobtrusive and theft-resistant form of vehicle-related data storage device that includes relatively high data capacity, security and re-write capability.